Force fit inflatable packer clamp

ABSTRACT

A force fit clamp for use in a field dressable inflatable packer for use in wells which includes a resilient sleeve disconnectably connected on a tubular member by the force fit clamping means.

Umted States atem 1191 1111 3,923,312

Hutchison et al. 1 Dec. 2, 1975 [5 FORCE FIT INFLATABLE PACKER CLAMP 2.827965 3/1958 Mouncc .1 277/34.6

2,328,823 4/1958 Mounce 277/346 [75] Inventors: Stanley O. Hutch1son, Bakersfleld 2332223 4/1958 Couraud 277/205 Neal Mltchell Taft, both Of (3811f 2,841,007 7/1953 Loomis 277/205 [73] Assignee: Chevron Research Company, San

Francisco Calif- Primary E.\'am1'nerR0bert 1. Smith 22 Filed: 10 1973 Attorney, Agent, or FirmEdward J. Keeling; R. L.

' Freeland, Jr. 211 App]. No.1 423,593

52 US. Cl 277/34.6; 277/205 [571 ABSTRACT [51] Int. Cl Fl6j 15/40 581 Field of Search 277/34, 34.6, 205 A force fit Clamp for use m a field dressable mflatable packer for use in wells which includes a resilient sleeve disconnectably connected on a tubular member [56] References Cited by the force f1t clamplng means. UNITED STATES PATENTS 2,826,784 3/1958 Pratt 7. 277/205 7 Claims, 4 Drawing Figures USO Pamm Dec. 2, 1975 FIG.3

FORCE FIT INFLATABLE PACKER CLAMP RELATED APPLICATIONS This application is related to application Ser. No. 367,602, filed June 6, 1973, and to application Ser. No. 430,326, filed Jan. 2, 1974.

BACKGROUND OF THE INVENTION This invention relates to an inflatable packer for use in wells and, more particularly, this invention relates to a force fit clamp which provides a disconnectable clamping means for connecting a resilient inflatable sleeve element of an inflatable packer to an inner tubular section of the packer to make for ease of assembly and disassembly of the packer under field conditions.

As is well known in the art inflatable packers have many uses in well operations. There have been, of course, many different embodiments of inflatable packers known and used heretofore. An inflatable packer generally includes an inner tubing section and a resilient element carried by the tubing section for sealing engagement with a well wall, casing or liner. Heretofore, inflatable packers have been rather complex, expensive pieces of apparatus which were not readily adaptable to low cost repetitive field operations. One exception, however, is an inflatable packer disclosed in my copending application Ser. No. 367,602. The present invention is also directed to providing a low cost field dressable inflatable packer for use in wells.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to a field dressable inflatable packer. An elongated resilient sleeve member is positioned over a tubing section. Force fit clamping means are provided to disconnectably connect the ends of the resilient member in fluid-tight relationship to the tubing section. Means are provided to inflate the resilient member to cause it to expand.

The clamping means of the present invention disconnectably connect at least one end of the resilient sleeve member to the tubing section in fluid-tight relationship therewith. A mandrel section having a central opening to slideably receive the tubing resilient member is provided with serrations on the outside of one end for engagement inside the resilient member. A force fit sleeve having inner annularly extending protuberances force fits over the mandrel section and is adapted to engage against the outside of the end of the resilient sleeve member. As the collar is forced down on the resilient member, the member is compressed between the outside of the mandrel section and the inside of the force fit sleeve. The resilient sleeve member is thus disconnectably connected between the mandrel section and the member force fit sleeve. Means are provided to maintain the sleeve and the mandrel section in position with respect to the tubing section to provide a suitable inflatable packer for field use.

OBJECTS OF THE INVENTION The principal object of the present invention is to provide a field dressable inflatable packer which includes a resilient sleeve disconnectably connected to a tubing section by means of a force fit clamp means. Further objects and advantages of the present invention will become apparent from the following detailed description read in light of the drawing which is a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view with portions broken away for clarity of presentation and illustrates the lower portion of apparatus assembled in accordance with the present invention;

FIG. 2 is an elevation view and a continuation of FIG. 1 and illustrates the upper portion of apparatus assembled in accordance with the present invention;

FIG. 3 is a section view taken at line 3-3 of FIG. 2;

and

FIG. 4 is a sectional view taken at line 4-4 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred arrangement of apparatus of the present invention will now be described in detail with reference to the drawings and to FIGS. 1 and 2 in particular. The apparatus of the present invention provides an inflatable packer useful in well operations. The inflatable packer utilizes force fit clamping means which includes a mandrel section and a force fit sleeve cooperating to disconnectably connect one end of an inflatable sleeve element therebetween. The resilient member and the mandrel section fit over the tubing section which extends through the resilient sleeve member. A second clamping means is used to secure the other end of the resilient sleeve member on the tubing section. Thus, the resilient sleeve member is connected in fluid-tight relationship over the tubing section. Fluid is forced between the inside of the resilient member and the outside of the tubing section to inflate the resilient member to sealingly engage the inside of a well. The inflatable packer is illustrated inside of well casing 22. The casing 22 is used to line the wall of the well as is known in the art.

An inflatable resilient sleeve member 10 is disconnectably connected at its upper and lower ends in fluidtight relationship to an elongated tubing section 12. The connection is made by releasable force fit clamping means indicated generally by the numerals 14 and 16. The'tubing section 12 extends through the clamping means 14 and I16. The upper end of the tubing section 12 is usually connected into a segmented tubing string which extends to the top of the well. If desired, however, the tubing section may be connected through an appropriate linkage system to a wireline. In this event, suitable inflation devices for inflating the inflatable element are run into the well with the tubing section on the wireline. When the tubing section is run into the well on a segmented tubing string, the resilient sleeve member 10 is inflated by flowing a fluid such as gas or liquid down the interior of the tubing string into the tubing section and then through the tubing section through a suitable hole or holes 20 therein provided.

The lower end of the tubing section 12 is connected to a float shoe 24 by means of an intermediate sub 26. The float shoe 24 has a plurality of holes 28 to permit entry of well fluids into the interior of the shoe 24. An

upwardly opening check valve, such as flapper valve 30, is located in the float shoe 24 above the holes 28. When the flapper valve is open, well fluids can communicate with the interior of the tubing section 12 and the other tubing connected thereabove.

When well liquids are encountered when the inflatable packer of the present invention is being run into a well on a segmentedtubing string, the flapper valve 30 opens to permit entry of the well fluids into the interior of the tubing section 12 and the tubing string. This equalizes the pressure on the interior and the exterior of the packer and permits later inflation of the inflatable resilient sleeve member by means of a relatively small pressure differential. This is so because the pressure needed to inflate the resilient sleeve does not need to overcome the well pressure.

When fluid is injected into the tubing section from above to apply pressure to the inflatable resilient sleeve member 10 the flipper valve is closed by the pressure and the resilient member 10 is expanded by means of flow into the annular chamber 11 between the tubing section 12 and the resilient sleeve member 10. Even though a column of well liquids may extend up the interior of the tubing and into the annular chamber 11 the packer is still inflated by pressurizing the tubing string from the surface. After the inflatable packer operation is completed and it is desired to deflate the packer and remove it from the well, a drain port is opened below the tubing section 12 to allow the interior of the tubing to drain. Thus knock-off plug 32 is positioned in the adapter sub 26. A sinker bar (not shown) is used to shear off the back of the plug 32 to open communication from the inside of the tubing to the well annulus. If desired, a sliding sleeve valve may be used instead of the knock-off plug.

The inflatable resilient sleeve member 10 of the packer is preferably formed of rubber on a rubber-like material. The sleeve must be capable of being expanded and retracted numerous times. In preferred form the resilient sleeve is formed by extruding a sleeve of rubber stock material of suitable diameter for the particular packer desired. Suitable reinforcing may also be desirable in the rubber sleeve. Physical properties of the rubber used in one suitable resilient sleeve were found to be as follows: elongation 450% minimum; tensile strength 2500 lbs./in. shore hardness 70; and tear 250 lbs/inch.

The inflatable sleeve member 10 of the packer is connected at its upper and lower ends in fluid-tight relationship by force fit clamping means 14 and 16. The clamping means 14 and 16 disconnectably connect the flexible sleeve 10 in position over the tubing section 12. The disconnectable connection provided by the clamping means permits easy field repair or dressing of the packer. Thus if the ends of the sleeve wear or abrade near the clamping means, then one or more of the clamps is opened and the worn end of ends of the sleeve trimmed off. The sleeve is then reconnected into the clamping means and the packer is again ready for use.

The clamping means of the present invention includes a mandrel section 34 which fits closely in sliding relationship over the tubing section 12. The outside surface of the mandrel has a number of annularly extending serrations 46. Since the clamping means is slideable on the tubular section it may be repositioned on the tubular section to accommodate a resilient sleeve member which has been shortened by field dressing. A pair of interior O-rings 36 and 38 located between the inside of the mandrel and the outside of the tubing section provide a fluidtight seal between the tubing section 12 and the mandrel section 34. Retaining rings 40 and 42 are connected in selected grooves on the exterior of the tubing section 12 above and below the mandrel section 34 to limit the movement of the clamping means on the tubing section. It is noted that the retaining rings 40 and 42 can easily be snapped off and repositioned in other grooves located on the tubing section 12. Thus if the flexible sleeve 10 is shortened during field dressing, the retaining rings 40 and 42 are disconnected and the serrated mandrel and the force fit sleeve of the clamping means are moved to a new position on the tubing section 12 and the retaining rings connected to a groove located at such location. In this regard, a series of grooves may be formed at convenient locations on the tubing section so that shortening of the resilient sleeve member may be done and retaining rings connected to the tubing to secure the clamping means holding the shortened resilient sleeve in place. A force fit sleeve 52 cooperates with the mandrel section to releasably hold one end of the resilient sleeve member 10. The shortened resilient sleeve is then reconnected to the tubing strip by the clamping means at such position.

The outside portion of the mandrel 34 which engages the resilient sleeve 10 has a series of radially extending serrations 46 located on one end beneath aflange 44 formed on the upper portion of the mandrel 34. The portion of the mandrel above the flange 44 is provided with a groove which contains a retaining ring 54 to prevent sleeve 52 from undesirable upward movement. The interior of sleeve 52 is provided with annular protuberances 48 which cooperate with the serrated portion of the mandrel section 34 to grip an end of the re silient sleeve 10. A shoulder on the sleeve 46 mates with the radial flange 44 of the mandrel section to limit travel of the sleeve over the mandrel section. The sleeve and the mandrel cooperate to disconnectably hold the end of the resilient sleeve member. The resilient member may be connected or disconnected by utilizing a pneumatic or hydraulic jack to force the force fit sleeve 52 up over the mandrel section 34. Retaining ring 4(1) is useful during such an operation to limit travel of the mandrel section 34 so that the sleeve 52 may be slipped off. Connection of the sleeve 52 and the mandrel around the end of the resilient member and is done by forcing the sleeve down over the resilient member. Retaining ring 42 keeps the mandrel from slipping along the tubing during the make up operation.

The inflatable packer of the present invention is readily assembled. The tubing section 12 is placed in a suitable position to receive the inflatable resilient sleeve member 16. One end of the resilient sleeve 10 is trimmed and beveled on the exterior surface as shown in FIG. 2. The resilient sleeve member 10 is slid over the tubing section 12 and an inside retaining ring 42 is snapped into a groove at a desired location on the tubing section 12. The mandrel section 34 is slipped over the end of the tubing section 12 and moved to contact retaining ring 42. An outer retaining ring 40 is then installed in a groove in tubing section 12 on the other side of the mandrel 34. The resilient sleeve member 10 is then slipped over the outside of the mandrel 34 and is butted against a flange 44 formed on the upper exterior portion of the mandrel 34. The other end of the resilient sleeve member is cut to a predetermined length and is beveled for connection into clamp ing means 14. The retaining ring 40 on the other end of tubing section 12 is removed and the mandrel section 34 and the resilient sleeve member 10 are moved up the tubing section 12 to expose a groove for the inside retaining ring (not shown) of clamping means 14. A retaining ring is installed in this groove and a mandril section 53 is slipped over the lower end-of tubing section 12 in contact with this retaining ring. An outside retaining ring 51 is then positioned in a groove on the tubing section 12 on the other side of the mandrel 53. The resilient sleeve and the upper mandrel 34 are then moved down the tubing section 12 to permit the other end of the resilient sleeve member 10 to be forced over the outer portion of the lower mandrel 53. Forced fit sleeves 52 and 55 are placed over the tubing section 12 in position to be installed over the ends of the resilient sleeve 10. The forced fit sleeves 52 and 55 are formed over the resilient sleeve member 10 by suitable means such as a hydraulic jack. After the forced fit sleeves 52 and 55 are in position, the outside retaining rings 50, 51 and 40, 54 are installed and the packer is ready to be run.

The inflatable packer is also readily repaired in the field if the resilient sleeve member 10 is damaged near a clamping means. If, for example, a portion of the inflatable resilient sleeve member 10 were damaged near the clamping means indicated generally at 16, field repair of the packer is readily accomplished as set out below in detail. The retaining ring 54 positioned in a groove on mandrel section 34 is removed and the force fit sleeve 52 is removed from the mandrel section 34. The damaged portion of the resilient sleeve member 10 is cut off by suitable means such as a sharp knife. The cut is located so that it removes the damaged portion of the sleeve member 10 and so that the shortened sleeve member 10 is in proper location with respect to other retaining ring grooves located on the tubing section 12. The retaining ring 51 on the other end of the tubing section is removed and the resilient sleeve member 10 and the clamping means indicated generally by 14 are moved to expose a new retaining ring groove on the other end of the tubing section 12. A retaining ring is connected into this groove and the mandrel 34 is moved in position adjacent this ring. A retaining ring is snapped into a groove on tubing section 12 above the mandrel 34 in this new position. The resilient sleeve member 10 is then moved over the mandrel 34 in a position abutting flange 44. The force fit sleeve 52 is then forced over the end of the resilient groove member 10 to reconnect the resilient sleeve member. Retaining ring 54 is replaced to locate the force fit sleeve in place. Retaining ring 51 is positioned at the other end of the packer to complete the connection.

Typically, the resilient sleeve member 10 is formed by extruding a rubber tube in a manner well known in the art. The rubber is cured to an appropriate extent and is cut to a desired length. Resilient sleeve members up to 33 feet in length have been used in accordance with the present invention. Typical dimensions of resilient sleeve members and force fit clamping means which have provided good results in field operations are set out below. A relatively small diameter tube was successfully connected by the force fit clamping means of the present invention. The rubber tube had an inside diameter of 2% inches and an outside diameter of 2% inches. The outside diameter of the mandrel section including the annularly extending serration 46 was 2.50 inches and the inside diameter of the annular protuberances 48 of the force fit sleeve 52 were 2.90 inches. In a larger packer a resilient sleeve member was formed having an inside diameter of 3% inches and an outside diameter of 4V2 inches. In this instance a mandrel section was used having an outside diameter of 3.387 inches including the serration. The inside diameter of the annularly extending protuberance of the force fit sleeve 52 was 4.453 inches. In the case of the smaller packer a ram force of between 5,600 to 7,000 pounds was used to connect the force fit sleeve over the mandrel. In the larger packers from 10,600 to 14,100 pounds of ram force were used to make this connection.

Thus in summary the present invention provides a field dressable inflatable packer which includes an elongated resilient sleeve positioned over a tubing section. Force fit clamping means are provided to disconnectably connect the ends of the sleeve in fluid-tight relationship to the tubing section. Means are provided for inflating the sleeve to cause it to expand. The clamping means disconnectably connect at least one end of the resilient sleeve to the tubing section in fluidtight relationship therewith and includes a mandrel section having a central opening to slidably receive the tubing section. The mandrel is provided with serrations on the outside of one end for engagement inside the resilient sleeve. A force fit sleeve having inner protuberances fits over the mandrel section and is adapted to engage the outside of the end of the resilient sleeve member. As the sleeve is forced down on the resilient sleeve member the member is compressed and forced against the serrations of the mandrel. The resilient sleeve member is thus engaged between the mandrel section and the force fit sleeve.

Although certain preferred embodiments of the present invention have been herein described in order to provide an example of its construction and steps sufficient for usage by those skilled in the art, it is to be understood that various changes and innovations in the structure described can be effected without departure from the basic principles of the invention. Changes and revisions of this sort which continue to rely on these principles are therefore deemed to be circumscribed by the spirit and scope of the appended claims.

What is claimed is:

1. An inflatable packer comprising a tubing section, an elongated resilient sleeve member slideably positioned over said tubing section, force fit clamping means engaging said sleeve member and compressing said sleeve member near the ends thereof to disconnectably connect each end of said sleeve member in fluid-tight relationship with said tubing section to form an annular chamber between said tubing section and said sleeve member and port means providing a passageway for flowing fluid into said annular chamber to inflate said resilient sleeve member.

2. The packer of claim 1 further characterized in that said force fit clamping means are movable longitudinally with respect to said tubing section when said sleeve member is disconnected from said clamping means.

3. The packer of claim 2 further characterized in that retaining rings are connected to the exterior of said tubing section above and below said clamping means to limit the movement of said clamping means on said tubing section.

4. An inflatable packer comprising a tubing section, an elongated resilient sleeve member removably positioned over said tubing section and forming an annular chamber therewith, clamping means disconnectably connecting each end of said sleeve in fluid-tight relationship with said tubular section, said clamping means comprising a mandrel section slideably mounted in fluid-tight relationship on said tubular section and a cooperating force fit sleeve positioned over said mandrel section and cooperating with said mandrel section for receiving one end of said resilient sleeve member therebetween to compress said end in force fit relationship therebetween to provide a fluid-tight seal between said sleeve member and said tubing section.

5. The packer of claim 4 further characterized in that said clamping means are movable longitudinally with respect to said tubing section when said sleeve member therebetween. 

1. An inflatable packer comprising a tubing section, an elongated resilient sleeve member slideably positioned over said tubing section, force fit clamping means engaging said sleeve member and compressing said sleeve member near the ends thereof to disconnectably connect each end of said sleeve member in fluid-tight relationship with said tubing section to form an annular chamber between said tubing section and said sleeve member and port means providing a passageway for flowing fluid into said annular chamber to inflate said resilient sleeve member.
 2. The packer of claim 1 further characterized in that said force fit clamping means are movable longitudinally with respect to said tubing section when said sleeve member is disconnected from said clamping means.
 3. The packer of claim 2 further characterized in that retaining rings are connected to the exterior of said tubing section above and below said clamping means to limit the movement of said clamping means on said tubing section.
 4. An inflatable packer comprising a tubing section, an elongated resilient sleeve member removably positioned over said tubing section and forming an annular chamber therewith, clamping means disconnectably connecting each end of said sleeve in fluid-tight relationship with said tubular section, said clamping means comprising a mandrel section slideably mounted in fluid-tight relationship on said tubular section and a cooperating force fit sleeve positioned over said mandrel section and cooperating with said mandrel section for receiving one end of said resilient sleeve member therebetween to compress said end in force fit relationship therebetween to provide a fluid-tight seal between said sleeve member and said tubing section.
 5. The packer of claim 4 further characterized in that said clamping means are movable longitudinally with respect to said tubing section when said sleeve member is disconnected from said clamping means.
 6. The packer of claim 5 further characterized in that retaining rings are connected to the exterior of said tubing section above and below said clamping means to limit the movement of said clamping means on said tubing section.
 7. The packer of claim 4 further characterized in that said mandrel section has a plurality of radially extending stations on its exterior surface and said force fit collar has a plurality of annularly extending protuberances on its interior surface cooperating to secure said sleeve therebetween. 